In this contribution, we address laser-driven electron transport in fast ignition research and the need for ultra-fast (<10 fs) pump–probe diagnostics to study, on the microscopic level, current filamentation and related anomalous energy deposition. Rates of instability growth consistent with realistic fast ignition parameters are discussed. A 3D-hybrid-PIC simulation is presented as an illustrative case. The development of 5 fs PW-range laser pulses at MPQ is reported, which may generate ultra-bright VUV-, x-ray, electron and ion beam pulses to be used for ultra-fast plasma probing.